January Celestial Calendar by Dave Mitsky
All times are UT (subtract five hours, and one calendar day when appropriate, for EST)
1/1 Asteroid 4 Vesta is stationary at 21:00
1/2 The Moon is at apogee, subtending 29' 32" from a distance of 404,580 kilometers (251,394 miles), at 1:30; Mercury is at its southernmost declination (-24.7 degrees) at 12:00; Mercury (magnitude -0.9) is 1.5 degrees south of Jupiter (magnitude -1.8) at 16:00; the Lunar X (the Purbach or Werner Cross), an X-shaped clair-obscure illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to be fully formed at approximately 20:39
1/3 First Quarter Moon occurs at 4:45; Mars and Uranus are at heliocentric opposition (longitudes 215.3 degrees and 35.3 degrees) at 12:00
1/4 The peak of the Quadrantid meteor shower (40 to 120 or more per hour) is predicted to occur at 9:00; the Moon is 4.3 degrees southeast of Uranus at 23:00
1/5 The latest sunrise of the year at latitude 40 degrees north occurs today; the Earth is at perihelion (147,091,144 kilometers or 91,398,199 miles distant from the Sun) at 7:48
1/7 The Moon is 7.3 degrees southeast of the bright open cluster M45 (the Pleiades or Subaru) in Taurus at 4:00; the Moon is 3.0 degrees north of the first-magnitude star Aldebaran (Alpha Tauri) at 21:00
1/8 The latest onset of morning twilight of the year at latitude 40 degrees north occurs today
1/9 The Moon is 1.5 degrees southeast of the bright open cluster M35 in Gemini at 14:00; the Moon is at the ascending node (longitude 98.4 degrees) at 23:00
1/10 Mercury (1.43 astronomical units from the Earth at a latitude of -6.15 degrees) is in superior conjunction with the Sun at 15:00; a deep penumbral lunar eclipse visible from western Australia, Asia, Europe, Africa, extreme eastern South America, and extreme northern North America begins at 17:07; Full Moon (known as the Ice Moon, the Moon after Yule, the Old Moon, and the Wolf Moon) occurs at 19:21; the penumbral eclipse ends at 21:12; the Moon is 9.0 degrees south of the first-magnitude star Castor (Alpha Gemini) at 22:00
1/11 Uranus is stationary in longitude and resumes direct (i.e., eastward) motion at 0:00; the Moon is 5.3 degrees south of the first-magnitude star Pollux (Beta Gemini) at 3:00; Uranus is stationary in right ascension and resumes direct (i.e., eastward) motion at 6:00
1/12 The Moon is 1.0 degree north of the bright open cluster M44 (the Beehive Cluster or Praesepe) in Cancer at 0:00; Mercury (magnitude -1.2) is 2.0 degrees south of Saturn (magnitude +0.5) at 10:00
1/13 Pluto (at a distance of 34.94 astronomical units from the Earth at a latitude of -0.69 degree) is in conjunction with the Sun at 7:00; Saturn (at a distance of 11.02 astronomical units from the Earth at a latitude of 0.04 degree) is in conjunction with the Sun at 15:00; asteroid 1 Ceres in in conjunction at 18:00; the Moon is at perigee, subtending 32’ 39" from a distance of 365,958 kilometers (227,396 miles), at 20:21
1/16 Asteroid 5 Astraea (magnitude +8.9) is at opposition in Cancer at 7:00
1/17 The Moon is 7.1 degrees north-northeast of the first-magnitude star Spica (Alpha Virginis) at 9:00; Last Quarter Moon occurs at 12:58
1/18 The Curtiss Cross, an X-shaped clair-obscure illumination effect located between the craters Parry and Gambart, is predicted to be begin at 20:32
1/19 Mercury is at its southernmost latitude (-7.0 degrees) from the ecliptic plane at 12:00
1/20 The Sun enters Capricornus (longitude 299.7 degrees on the ecliptic) at 9:00; the Moon is 7.0 degrees north-northeast of the first-magnitude star Antares (Alpha Scorpii) at 18:00; the Moon is 2.2 degrees north-northeast of Mars at 21:00
1/22 The Moon is at the descending node (longitude 278.4 degrees) at 21:00
1/23 The Moon is 0.4 degree south of Jupiter, with an occultation occurring in southwestern Polynesia, southern and eastern Melanesia, New Zealand, southern and eastern Australia, Kerguelen Island, and Madagascar at 3:00; the Moon is 0.4 degree southeast of Jupiter at 3:00; Uranus is at eastern quadrature (90 degrees from the Sun) at 7:00
1/24 New Moon (lunation 1201) occurs at 21:42
1/27 Venus (magnitude -4.1) is 0.08 degree south of Neptune (magnitude +7.9) at 19:00
1/28 The Moon, Venus, and Neptune lie within a circle with a diameter of 3.9 degrees at 10:00; the Moon is 3.8 degrees southeast of Neptune at 10:00; the Moon is 3.8 degrees southeast of Venus at 10:00
1/29 The Moon is at apogee, subtending 29' 29" from a distance of 405,393 kilometers (251,899 miles), at 21:27
Johannes Hevelius (1611-1687), Ernst Abbe (1840-1905), George Van Biesbroeck (1880-1974), Luboš Kohoutek (1935), and Stephen Hawking (1942) were born this month.
Galileo Galilei discovered Io, Europa, and Callisto on January 7, 1610. Galileo Galilei discovered Ganymede on January 13, 1610. Nicolas-Louis de Lacaille discovered the emission nebula NGC 3372 (the Eta Carinae Nebula) on January 25, 1752. Charles Messier discovered the globular cluster M56 on January 23, 1779. Charles Messier discovered the globular cluster M80 on January 4, 1781. William Herschel discovered the spiral galaxy NGC 1084 on January 10, 1785. Pierre François André Méchain discovered Comet 2P/Encke on January 17, 1786. William Herschel discovered Titania and Oberon, two satellites of Uranus, on January 11, 1787. Giuseppe Piazzi discovered the first asteroid, 1 Ceres, on January 1, 1801. Louis Daguerre took the first photograph of the Moon on January 2, 1839. Alvan Clark discovered the white dwarf star Sirius B (the Pup) on January 31, 1862. The 36-inch Clark refractor at the Lick Observatory saw first light on January 3, 1888. Charles Perrine discovered the Jovian satellite Elara on January 2, 1905. Philibert Jacques Melotte discovered the Jovian satellite Pasiphae on January 27, 1908. Clyde Tombaugh photographed Pluto on January 23, 1930. Mike Brown, Chad Trujillo, and David Rabinowitz discovered Eris on January 5, 2005.
The Quadrantid meteor shower is predicted to peak around 4:00 a.m. EST on January 4th. The radiant lies at the junction of the constellations of Boötes, Hercules, and Draco, in what was once called Quadrans Muralis, and is highest just prior to dawn. A waxing gibbous Moon will not compromise the peak of this year’s Quadrantids. The Quadrantid shower can sometimes reach zenithal hourly rates of more than 100 meteors per hour for a relatively short period of time. The near-Earth asteroid 2003 EH1, which may be an extinct comet, is believed to be the source of these meteors. See pages 48 and 49 of the January 2020 issue of Sky & Telescope or https://amsmeteors.o...-meteor-shower/ for more on the Quadrantids.
Information on Iridium flares and passes of the ISS, the X-37B, the HST, and other satellites can be found at http://www.heavens-above.com/ and https://www.calsky.c...=42301117054103
The Moon is 5.6 days old, is illuminated 28.1%, subtends 29.8 arc minutes, and is located in Aquarius on January 1st at 0:00 UT. The Moon attains its greatest northern declination (+23.2 degrees) for the month on December 10th and greatest southern declination (-23.2 degrees) on December 23rd. Longitudinal libration is at a maximum of +5.4 degrees on December 21st. It’s at a minimum of -5.7 degrees on December 8th. Latitudinal libration is at a maximum of +6.9 degrees on December 3rd and +6.8 degrees on December 30th and a minimum of -6.8 degrees on December 16th. New Moon occurs on December 26th. The Moon is at perigee (distance 57.38 Earth-radii) on January 13th and at apogee (distance 63.43 Earth-radii) on January 2nd and again (distance 63.56 Earth-radii) on January 29th. A deep penumbral lunar eclipse, the 16th of Saros 144, reaches deepest eclipse in northwest India at 19:10:02 UT1 on January 10th. At maximum, 92% of the Moon will lie within the Earth’s penumbra. All four of the lunar eclipses that will occur in 2020 are penumbral. See http://www.eclipsewi...ml#LE2020Jan10N for further information. The Moon occults Jupiter on January 23rd from parts of the southern hemisphere. New Moon occurs on January 24th. Browse http://www.lunar-occ...ota/iotandx.htm for information on lunar occultation events. Visit https://saberdoesthe...does-the-stars/ for tips on spotting extreme crescent Moons and http://www.curtrenz.com/moon06.html for Full Moon data. Consult http://time.unitariu...moon/where.html or download http://www.ap-i.net/avl/en/start for current information on the Moon. See https://svs.gsfc.nasa.gov/4768 for a lunar phase and libration calculator and https://svs.gsfc.nasa.gov/4768 for the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap. Click on https://www.calendar...ar/2020/january for a lunar phase calendar for this month. Times and dates for the lunar crater light rays predicted to occur this month are available at http://www.lunar-occ...o/rays/rays.htm
The Sun is located in Sagittarius on January 1st. It enters Capricornus on January 20th
Data (magnitude, apparent size, illumination, and distance from the Earth in astronomical units) for the planets and Pluto on January 1st: Mercury (-0.9, 4.7", 99%, 1.43 a.u., Sagittarius), Venus (-4.0, 13.1", 82%, 1.28 a.u., Capricornus), Mars (+1.6, 4.3", 96%, 2.18 a.u., Libra), Jupiter (-1.8, 31.8", 100%, 6.21 a.u., Sagittarius), Saturn (+0.5, 15.1", 100%, 11.00 a.u., Sagittarius), Uranus (+5.8, 3.6", 100%, 19.67 a.u. on January 16th, Aries), Neptune (+7.9, 2.2", 100%, 30.54 a.u. on January 1 6th, Aquarius), Pluto (+14.4, 0.1", 100%, 34.94 a.u. on January 16th, Sagittarius).
During the evening, Mercury lies in the west, Venus and Neptune lie in the southwest, and Uranus lies in the south. At midnight, Uranus is in the west. Mars, Jupiter, and Saturn can be seen in the southwest in the morning.
Mercury is at its greatest heliocentric latitude south on January 19th. The speediest planet returns to the evening sky at twilight late in the month. Mercury shines at magnitude -1.0 and sets approximately 70 minutes after sunset as January draws to a close.
Venus lies in the southwest at an altitude of approximately 25 degrees at sunset on January 1st. Venus and Neptune undergo a very close conjunction on January 27th. By January 31st, Venus has climbed to about 34 degrees above the horizon and sets about 3.5 hours after the Sun. During January, Venus increases in apparent diameter from 13.2 arc seconds to 15.1 arc seconds but decreases in illumination from 82% to 74%.
Earth is 0.9832 a.u. distant from the Sun at perihelion on January 5th. On that date, it’s about 3% (5.0 million kilometers or 3.1 million miles) closer to the Sun than at aphelion on July 4th and about 2.7% closer to the Sun than on average.
Mars exits eastern Libra and enters Scorpius on January 7th and Ophiuchus on January 15th. The apparent brightness of Mars exceeds magnitude +1.5 on January 12th. Mars passes less than five degrees northwest of Antares, the Rival of Mars, on the mornings of January 17th and January 18th. Antares outshines Mars by about a half magnitude. A waning crescent Moon passes two degrees north of the Red Planet on January 20th. On January 25th, Mars is closer to the Earth than 2.0 astronomical units.
Jupiter appears low in the southeast during morning twilight after the second week of January. It rises more than 90 minutes before sunrise by the end of the month.
Saturn is in conjunction with the Sun on January 13th and is not potentially visible again until the end of the month.
Uranus is located 12 degrees south of the second-magnitude star Hamal (Alpha Arietis). The First Quarter Moon passes five degrees south-southeast of Uranus on January 14th. Uranus is at eastern quadrature on January 23rd. The seventh planet sets around midnight as January comes to a close. Visit http://www.nakedeyep....com/uranus.htm for a finder chart.
Neptune is located just five arc minutes north of Venus, the closest conjunction of the two planets since January 1984, on January 27th. It lies 12 arc minutes west of Venus a few hours later. Browse http://www.nakedeyep...com/neptune.htm for a finder chart.
Finder charts for Uranus and Neptune are also available online at https://s22380.pcdn....20_updated.pdf
See http://www.curtrenz.com/uranep.html for additional information on the two outer planets.
The dwarf planet Pluto is in conjunction with the Sun on January 13th.
For more on the planets and how to locate them, browse http://www.nakedeyeplanets.com/
A guide to planetary observing for the year by the British magazine The Sky at Night is posted at https://www.skyatnig...nets-night-sky/
Asteroid 4 Vesta shines at magnitude +7.5 as it heads northeastward through Cetus and Aries this month. It is stationary on January 1st and passes less than one degree to the east of the fourth-magnitude Mu Ceti on January 12th. Asteroids brighter than magnitude +11.0 that reach opposition this month include 192 Nausikaa (magnitude +10.0) on January 9th, 511 Davida (magnitude +9.6) on January 15th, 5 Astraea (magnitude +9.0) on January 21st, and 230 Athamantis (magnitude +10.7). Finder charts for 5 Astraea and 511 Davida can be found on page 49 of the January 2020 issue of Sky & Telescope. See http://asteroidoccul.../2020_01_si.htm for information on asteroid occultation events taking place this month. Consult http://www.curtrenz.com/asteroids.html to learn more about a number of asteroids.
During January, Comet C/2017 T2 (PanSTARRS) heads northwestward along the border of Cassiopeia and Perseus. It lies less than one degree north of the fourth-magnitude star Eta Cassiopeia on January 13th and less than one degree north of NGC 869 and NGC 884 (the Double Cluster) on January 26th and January 27th. Visit http://cometchasing.skyhound.com/ and http://www.aerith.ne...t/future-n.html for information on these and other comets visible this month.
The major meteor showers that will occur this year are discussed at https://www.skyandte...howers-in-2020/
Various events taking place within our solar system are discussed at http://www.bluewater...ed-4/index.html
Omicron2 (40) Eridani is a fourth-magnitude triple star system consisting of three dwarf stars: a type K1V yellow-orange dwarf [A] known as Keid, a type DA4 white dwarf [B], and a type M4.5e red dwarf [C]. Omicron is located about 16 light years from the Earth at 4h15m16.32s, -7°39′10.34″. Ninth-magnitude Omicron B is the most easily visible white dwarf star and can be seen with an aperture of six inches.
The famous eclipsing variable star Algol (Beta Persei) is at a minimum, decreasing in magnitude from 2.1 to 3.4, on January 2nd, 5th, 8th, 11th, 14th, 17th, 20th, 22nd, 25th, 28th, and 31st. The Demon Star is at minimum brightness for approximately two hours and is well-placed for observers in North America on the night of January 14th, centered at 1:46 a.m. EST. Minima can also be observed on the night of January 16th, centered at 10:36 p.m. EST, and on the evening of January 19th, centered at 7:25 p.m. EST. Consult page 50 of the January 2020 issue of Sky & Telescope for the times of the minima. For more on Algol, see http://stars.astro.i.../sow/Algol.html and http://www.solstatio...rs2/algol3.htm
Data on current supernovae can be found at http://www.rochester...y.org/snimages/
Information on observing some of the more prominent Messier galaxies is available at http://www.cloudynig...ur-astronomers/
One hundred and five binary and multiple stars for January: Omega Aurigae, 5 Aurigae, Struve 644, 14 Aurigae, Struve 698, Struve 718, 26 Aurigae, Struve 764, Struve 796, Struve 811, Theta Aurigae (Auriga); Struve 485, 1 Camelopardalis, Struve 587, Beta Camelopardalis, 11 & 12 Camelopardalis, Struve 638, Struve 677, 29 Camelopardalis, Struve 780 (Camelopardalis); h3628, Struve 560, Struve 570, Struve 571, Struve 576, 55 Eridani, Struve 596, Struve 631, Struve 636, 66 Eridani, Struve 649 (Eridanus); Kappa Leporis, South 473, South 476, h3750, h3752, h3759, Beta Leporis, Alpha Leporis, h3780, Lallande 1, h3788, Gamma Leporis (Lepus); Struve 627, Struve 630, Struve 652, Phi Orionis, Otto Struve 517, Beta Orionis (Rigel), Struve 664, Tau Orionis, Burnham 189, h697, Struve 701, Eta Orionis, h2268, 31 Orionis, 33 Orionis, Delta Orionis (Mintaka), Struve 734, Struve 747, Lambda Orionis, Theta-1 Orionis (the Trapezium), Theta-2 Orionis, Iota Orionis, Struve 750, Struve 754, Sigma Orionis, Zeta Orionis (Alnitak), Struve 790, 52 Orionis, Struve 816, 59 Orionis, 60 Orionis (Orion); Struve 476, Espin 878, Struve 521, Struve 533, 56 Persei, Struve 552, 57 Persei (Perseus); Struve 479, Otto Struve 70, Struve 495, Otto Struve 72, Struve 510, 47 Tauri, Struve 517, Struve 523, Phi Tauri, Burnham 87, Xi Tauri, 62 Tauri, Kappa & 67 Tauri, Struve 548, Otto Struve 84, Struve 562, 88 Tauri, Struve 572, Tau Tauri, Struve 598, Struve 623, Struve 645, Struve 670, Struve 674, Struve 680, 111 Tauri, 114 Tauri, 118 Tauri, Struve 730, Struve 742, 133 Tauri (Taurus)
Notable carbon star for January: R Leporis (Hind’s Crimson Star)
Seventy deep-sky objects for January: B26-28, B29, M36, M37, M38, NGC 1664, NGC 1778, NGC 1857, NGC 1893, NGC 1907, NGC 1931 (Auriga); IC 361, Kemble 1 (Kemble’s Cascade asterism), NGC 1501, NGC 1502, NGC 1530, NGC 1569 (Camelopardalis); NGC 1507, NGC 1518, NGC 1531, NGC 1532, NGC 1535, NGC 1537, NGC 1600, NGC 1637, NGC 1659, NGC 1700 (Eridanus); IC 418, M79, NGC 1832, NGC 1888, NGC 1964 (Lepus); B33, Cr65, Cr69, Cr70, IC 434, M42, M43, M78, NGC 1662, NGC 1973-75-77, NGC 1981, NGC 1999, NGC 2022, NGC 2023, NGC 2024, NGC 2112 (Orion); Be11, NGC 1491, NGC 1496, NGC 1499, NGC 1513, NGC 1528, NGC 1545, NGC 1548, NGC 1579, NGC 1582, NGC 1605, NGC 1624 (Perseus); DoDz3, DoDz4, M1, Mel 25, NGC 1514, NGC 1587, NGC 1647, NGC 1746, NGC 1807, NGC 1817 (Taurus)
Top ten binocular deep-sky objects for January: Cr65, Kemble 1, M36, M37, M38, M42, NGC 1528, NGC 1647, NGC 1746, NGC 1981
Top ten deep-sky objects for January: M1, M36, M37, M38, M42, M43, M78, M79, NGC 1501, NGC 2024
Challenge deep-sky object for January: IC 2118 (Eridanus)
The objects listed above are located between 4:00 and 6:00 hours of right ascension.